The Influence of Salmon Availability on Movements and Range of Brown Bears on Southwest Author(s): Victor G. Barnes, Jr. Source: Bears: Their Biology and Management, Vol. 8, A Selection of Papers from the Eighth International Conference on Bear Research and Management, Victoria, British Columbia, Canada, February 1989 (1990), pp. 305-313 Published by: International Association of Bear Research and Management Stable URL: http://www.jstor.org/stable/3872933 Accessed: 03/01/2009 19:59

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http://www.jstor.org THE INFLUENCEOF SALMONAVAILABILITY ON MOVEMENTSAND RANGEOF BROWNBEARS ON SOUTHWESTKODIAK ISLAND

VICTOR G. BARNES, JR. U.S. Fish and Wildlife Service, 1390 Buskin River Road,Kodiak, 99615

Abstract: Brown bear (Ursus arctos middendorffi) movements and seasonal range were examined in relation to the temporal and spatial distribution of salmon (Oncorhynchus spp.) on southwest Kodiak Island, Alaska, from 1983 to 1987. Salmon were available to bears from late June to mid-December and were utilized by all sex and age classes. From 50-89% of adult females fished at >2 separate areas of salmon abundance each year. Mean composite summer range of females tracked 2- 5 yrs (108 km2)was much greaterthan either spring (13 km2)or fall (26 km2)range. Annual summerrange of 8 females tracked4 consecutive years averaged40 km2; a smaller mean area of primary use (12 km2) reflected a pattern of movement between areas of concentrated food. Females did not restrict their movement patterns in years they were accompanied by new (<1 yr) cubs. Males fished for salmon at the same sites used by females but traveled between those areas more often than females. Annual variation in movement patterns was due apparently to behavioral differences among individual bears as well as yearly fluctuations in berry production, salmon availability,and unknownfactors. Importantbear feeding areas in this region can be conserved by monitoringsalmon escapementstogether with associated bear use, and by restrictinghuman access at particularsites.

Int. Conf. Bear Res. and Manage. 8:305-313

Pacific salmon are an importantcomponent of brown manuscripttyping. G. Garer, D. Reinhart,J. Schoen, L. bearhabitat (Kistchinski 1972, Berns et al. 1980, Schoen Van Daele, and 2 anonymousreferees provided helpful et al. 1986, Hamilton and Bunnell 1987) as well as a reviews of the manuscript. valuable commercial and recreationalresource. Shared use of the salmon resource and cohabitationof anadro- STUDY AREA mous streamhabitat humans and bears man- by present Kodiak Island is located in the Gulf of Alaska at 56- agementproblems such as depletionof fish stocks (Shu- 58? North latitude and 152-155? West longitude. The man 1950, Clark 1959, Gard 1971), safety to people study area encompassedabout 2,700 km2on southwest (Meehanand Thilenius 1983, Miller and Chihuly 1986), Kodiak Island (Fig. 1). The region has a cool, maritime and adverse impacts on bears from human disturbance climate characterizedby cloudy days, summertimefog, (Archibaldet al. 1987, Warner1987). and frequentwind. Summertemperatures usually range Brown bearson KodiakIsland occur at high densities from 13 to 18 C and wintertemperatures below -6 C are (Troyer and Hensel 1964, Barnes et al. 1988) and are uncommon.Annual precipitation averages about 150 cm. highly sought after by trophyhunters. Increasingnum- The western portion of the study area has wide, flat bers of people visit the island to photographor simply valleys, rolling foothills, and few ridges above 600 m. observe the animals. A major objective of the Kodiak Topographybecomes progressivelymore rugged in east- National Wildlife Refuge, which encompasses most of ern partsof this area;steep valley walls are common and the southerntwo-thirds of Kodiak Island, is to maintain high qualitybrown bear habitat for the enjoymentof both consumptiveand non-consumptiveusers (U.S. Fish and Wildlife Service 1987:179). Identifyingimportant bear habitatand the factorsthat influence use of thathabitat is a key management strategy. In this paper, I examine brownbear movements and seasonaluse in relationto the temporal and spatial distributionof spawning salmon. This work is partof a largerinvestigation of habitatuse and census methodology. I thankthe numerousemployees andvolunteers of the U.S. Fish andWildlife Service, the AlaskaDepartment of Fish andGame, and several aircraft charter companies for their assistance. Essential support and guidance were provided by J. Bellinger, B. Palmisano, L. Pank, R. Smith, and C. Strickland(deceased). I extend thanksto J. Selinger for datasummarization, to C. Robbinsand D. Douglas for computeranalyses, and G. Castonguayfor Fig. 1. Features of the study area in southwest Kodiak Island, Alaska. 306 BEARS-THEIR BIOLOGY AND MANAGEMENT numerouspeaks extend above 900 m. Poorly drained METHODS lowlandsare vegetated by a mosaic of willow (Salix spp.) Brown bears were capturedby dartingfrom helicop- and herbaceouscover, while well-drainedsites are com- ters duringmid-May to late July from 1983 to 1987. All monly dominated by hummocks covered with heath adults (>5 yr) and selected subadults(<5 yr) were fitted (Ericaceae) and bluejointgrass (Calamagrostiscanad- with radio-collars;adult females were recapturedand ensis). Mid-slope habitatconsists of dense to scattered fitted with new radio-collarsat 2-3 year intervals. Cap- alder(Alnus crispa) patchesinterspersed with red elder- ture effort was directed exclusively at adult females berry(Sambucus racemosa); representative vegetation in during 1983-1985, but included some adult males and openings includes bluejoint grass, sedge (Carex spp.), subadultsfor populationstudies (Barnes et al. 1988) in ferns (Polypodiaceae), fireweed (Epilobiumangustifo- 1986 and 1987. Bears were radio-trackedfrom fixed- lium), cow parsnip(Heracleum lanatum), and salmon- wing aircraftat 7-10 day intervalsfrom Marchthrough berry(Rubus spectabilis). Alpinehabitat consists of low- Novemberand at roughly 2-3 week intervalsduring the growing willow, heath, herbaceousmeadows, bare soil, remainderof the year. Bearswere occasionallyrelocated and rock. >1 time per week during capture operations or while Six species of Pacific salmon spawn in the study area surveyingbear concentrationsduring summer. Habitat (Table 1). The Karlukand AyakulikRiver drainages are type, elevation, activity, associated bears, and relative the 2 largest watersheds on Kodiak Island and each food availabilitywere recordedat the time each bearwas supportssignificant runs of sockeye (0. nerka),chinook relocated. Locationswere plottedon 1:63,360 scale U.S. (0. tshawytscha), pink (0. gorbuscha), and coho Geological Surveytopographic maps. These pointswere (0. kisutch)salmon as well as steelheadtrout (0. mykiss). subsequentlydigitized for computer analysis with the Othermajor drainages(Table 1) support2-4 important mapoverlay and statistical system (MOSS)developed by salmonruns and numerous little streamshave small runs, the U.S. Departmentof the Interior. usually of pink, chum (0. keta) or . Except Supplemental information on bear concentrations, for sockeye in the FrazerLake system, all of the salmon bear activity, and salmon availability were recorded and steelheadruns are naturalpopulations. A fish pass while conductingaerial stream surveys of bearsand from built in 1962 on Dog SalmonCreek allows an artificially campsestablished on ridgesoverlooking streams utilized establishedrun of sockeye to migrateinto FrazerLake. by bears.

1983-1987. Table 1. Spawning escapements and seasonal availability of salmon species utilized by brown bear on southwest Kodiak Island, Alaska,

Average escapement(thousands), 1983-1987a Seasonal availabilityb Sockeye Chinook Chum Pink Coho Spring Summer Fall

KarlukLake System 701.2 7.4 <0.5 489.0 31.6 River SO,CI,PI SO,CO Lake SO SO SO,CO

AyakulikRiver 245.7 10.4 <0.5 243.9 17.6 Main SO,CI,PI,CO CO East Fork SO,CI CO Red Lake SO SO SO,CO

FrazerLake System 182.4 <0.5 15.0 95.6 4.1 Dog Salmon Ck. SO SO,CU,PI Pinnell Ck.SO

SturgeonRiver 52.3 8.8 3.0 CU CU CO Uyak River 12.9 116.2 Unk. CU,PI DeadmanRiver 17.7 113.6 Unk. CU,PI a Weir and aerial survey data (Alaska Dep. Fish and Game and Kodiak Natl. Wildl. Refuge files). b = = = Summer= - Fall = Oct. - Nov. Species: SO = sockeye, CI = chinook, CU = chum, PI pink, CO coho; Season: Spring late June, July Sept., SALMONINFLUENCE ON BROWNBEAR * Barnes 307

The extent that bears traveled in response to salmon Salmon Creek (8%) watersheds. Thirty-three adult availability was evaluated by recordingthe numberof females were tracked>2 consecutive years and 6 adult times they visited different fishing areas. These areas males were trackedfor 1 to 2 years;the following results were subjectively chosen to represent exploitation of arebased primarily on dataassociated with 2,529 reloca- salmon in different drainages or feeding on a single tions of these animals. species in distinctportions of the same watershed.In the AyakulikRiver drainage,for example, bearsfeeding on Patterns of Salmon Use chinook salmonin the riversegment below the Red Lake Bears fed on salmon at various sites in the study area subdrainagewere classed separatelyfrom bears feeding fromlate Juneto mid-December.They beganfeeding on on the same species in the AyakulikEast Fork. Similarly, in SturgeonRiver, and on for bears feeding on sockeye, the Red Lake system and in Dog Salmon Creek and Karlukand Red Lake drain- the Ayakulik East Fork were considered 2 different ages, fromlate June to earlyJuly (Fig. 1, Table 1). During fishing areas. However, a bear feeding on different July andAugust, bears fed extensively on chinook, sock- salmon species at the same location, regardlessof time, eye, chum or at numerouslocations. From was considered to have visited only 1 fishing area. If middle or late August to mid-September,bears used bearswere not fishing along or in a stream,they were not streamsless andspent increasing time foragingfor elder- recordedas utilizingsalmon unless spawningsalmon and berriesand salmonberries (Clark 1957, Berns et al. 1980). evidence of feeding on salmon (trails, beds, salmon This patternvaried annually relative to berryproduction, carcasses) were apparentin the drainagewhere the bear but bears continued to feed on salmon to some degree was located. regardless of berry abundance. Each year from late I used programHOME RANGE (Samuelet al. 1985) August to middle or late September,bears also congre- to estimate seasonalranges and areasof primaryutiliza- gated along streamsat the head of Uyak Bay to feed on tion. The 95% minimum convex polygon was used to chumand pink salmon. In late Augustand early Septem- estimatetotal range exclusive of outlierlocations and the ber of 1986, an unusual number (9) of radio-collared 95% harmonicmean contour was used to estimate the bears traveledto the lower Ayakulik River or to distant area most heavily utilized by bears. Because the 95% small streams(Carmel Creek, Grants Lagoon) to feed on harmonicmean contouroften excluded travelcorridors, chinook or pink salmon. for especially wide-ranging animals, it generally en- Heavy use of sockeye salmon continued through closed an areasmaller than the 95%convex polygon. For Septemberin the Karlukand Red Lake basins as bears seasonal I defined ranges, spring, summer and fall as graduallyshifted emphasisfrom fish spawningin tribu- May-June, July-September, and October-November, tary streamsto those spawningalong lake shores. Bears Movements in respectively. April and December were consistently fed on beach-spawning sockeye salmon omitted from because substantial analysis numbers of through October in both areas; use declined in early bear were denned in those months (Van Daele et al. November at Red Lake but some animals continued to 1990). For comparisonswith other studies, I also deter- feed along Karluk Lake shores until mid-December. mined home 100%minimum rangesusing convex poly- Utilizationof coho salmon began in September,peaked gons. in October,and declined duringNovember. Two adult The Kruskal-Wallistest of significance was used for males and 2 adult females continued to feed on coho comparisons of range size among seasons, years, and salmonin tributariesof the KarlukRiver into December. females of different maternalstatus. The Chi-squared Migratingor spawningsteelhead trout appeared to be statisticwas used to analyze frequencydistributions. only incidentalprey of brownbears. Substantialmove- ment of steelhead into the Karlukand Ayakulik Rivers RESULTS did not occur until late Septemberor early November Seventy-one bears were radio-collaredfrom 1983 to (Chatto 1987) and at that time coho salmon were more 1987, including 57 adult females, 7 adult males and 7 widely distributedand abundant. Bear predation on subadults. With the exception of 1 male captured at spawningsteelhead was notedas earlyas mid-Mayin the Karluk all the animals Lake, were initiallycaught west of UpperEast Forkof the AyakulikRiver, but most spawn- the KarlukLake and River watershedand northof Olga ing took place in larger riffle areas downstreamwhere Bay (Fig. 1). Most (51%) captureswere made in Stur- steelheadcould betterevade bears. and geon AyakulikEast Fork River drainages,followed All radio-collaredbears (including 6 subadults)moni- by the Pinnell Creek (18%), Red Lake (13%) and Dog tored at least 1 summer season utilized salmon. Inter- 308 BEARS-THEIR BIOLOGY AND MANAGEMENT drainagemovement of radio-collaredbears was common most radio-trackingflights (>1 week) probablyallowed as they respondedto changes in salmon abundanceor some movementto go undetected. distribution. As the chum salmon run declined in Stur- Causes of annual variability in the frequency that geon River, bears usually traveledto Red Lake, Karluk females used 1, 2, or >3 fishing areas were not clear Lake,or Pinnell Creekto feed on sockeye salmon. Often (X2= 30.8, P < 0.05). A relativelysparse elderberry crop these animalsreturned to the SturgeonRiver drainageto in 1986 may have contributedto high interchangeamong feed on berries,fish for coho salmon, and begin winter fishing areasthat year. However,differences in behavior denning. Bears thatfed on the early sockeye run in Dog, of individual animals as well as subtle fluctuationsin Salmon Creek either remained there to fish for chum abundance of salmon or other foods may also have salmon,traveled to the Red or KarlukLake area to exploit influenced bear movements in 1986 and other years. sockeye salmon,or moved to the DeadmanRiver to feed Overall73% of the radio-collaredfemales annuallyused on chum and pink salmon. Interchangebetween Karluk >2 fishing areas. Lake and Pinnell Creek,and between Pinnell Creekand Limited data on adult males (Table 2) suggest they Red Lake, was frequently observed. Long distance traveledmore extensively duringsummer than did adult movementsto and from areaseast of KarlukLake were females. All 6 males fished >3 areaseach year;the mean recordedfor 2 females and 1 male. numberof areas visited in 1986 and 1987, respectively, Data were inadequatefor most bears to determine were 4.3 and 3.5 for a combined averageof 3.9. movement patternsduring periods <1 week. However, Some fishing areas consistently attractedhigh num- some insight was obtainedfrom a female radio-collared bers of markedand unmarkedbears (Table 3). The Red in 1987 thatyielded locations at 1- to 3-day intervalsvia Lake system was visited by an average of 43% of the satellite (Fancy et al. 1988). She and her 2, 2-year-old females and all males under study each year. Twenty- cubs utilized a small area along SturgeonRiver the last seven (69%) of 39 adultbears fished in Red Lake and/or half of July, remainedalong a tributaryof Red Lake the its tributariesat least once duringthe study. One 6.5 km first 8 to 10 days of August,moved to the lower Ayakulik streamreceived particularlyheavy use; peak counts of River from 10-26 August and returnedto the Sturgeon aerialsurveys of the streamaveraged 38 bearsfrom 1984 Riverby 29 August. She was observedfishing for chum, to 1987. Observers at ridge-top camps identified a sockeye, and chinook salmonat the SturgeonRiver, Red minimumof 86 and49 individualbears (including young) Lake, and Ayakulik River sites, respectively. Neither using the streamduring 4-day periodsin early August of satellite nor conventionalaircraft tracking indicated she 1986 and 1987, respectively. moved back and forth between those areas during that The upperstretches of SturgeonRiver also sustained period. heavy and consistent use by bear;23-41% of the radio- The meannumber of differentfishing areasindividual collared females fished in the river each year (Table 3). females visited each yearranged from 1.6 (1983,1987) to Fifteen (45%) of 33 females and 3 of 6 males fished the 2.6 (1986) and averaged 2.1 (Table 2). These figures SturgeonRiver at least once duringthe study. Peakaerial provide a conservative measure of movement because counts of this streamaveraged 43 bearsduring 1984-87. some bears fished in the same area at 2 separatetimes an excursionto fish at a distantsite. Bears interruptedby Movements and Seasonal Range also moved to and from where salmon runs drainages Movements of most (85%) adult females tracked>2 were simultaneously; the interval between occurring years were confined to a core area that was boundedby the KarlukRiver and Dog SalmonCreek drainages on the Table 2. Annual variation in number of salmon fishing areas used by radio- east, Olga Bay on the south, and the Pacific Coast on the collared adult brown bears, southwest Kodiak Island, Alaska. west (Fig. 1); all of them dennedwithin thatarea. Mean annualrange (95% minimum convex) of these 29 females No. Females Males was 52 km2and only 1 had a mean annualrange >80 km2. areas for 4 visited 1983 1984 1985 1986 1987 1986 1987 A contrastingpattern of movement was evident other females that denned east or southeastof this core - 1 7 6 4 3 9 area. In 14 of 16 bear-yearsthey were tracked,these 4 - 2 5 15 16 8 9 animalsfished at 1 or more sites in the core areaand then 3 2 4 6 13 1 - 3 traveledeast to areas in which they eventually denned. 4 - 1 4 - 2 Threeof them also,fedon salmonin the drainageswhere 5 - 1 1 they denned. The 4th female may have fed on coho SALMONINFLUENCE ON BROWNBEAR * Barnes 309

Table 3. Annual use of fishing areas by adult radio-collared brown bears, southwest Kodiak Island, Alaska.

Females Males Fishing 1983 1984 1985 1986 1987 1986 1987 area (n = 14) (n = 25) (n = 27) (n = 28) (n = 19) (n = 3) (n = 4)

Red Lake Systema 3 5 14 18 8 3 4 SturgeonRiver 3 9 8 12 6 1 2 Pinnell Creek 4 5 7 8 3 3 1

KarlukLake Systemb 4 7 8 6 1 1 1 East Fork AyakulikRiver 3 7 6 7 3 1 3 Deadman/UyakRivers, Combined 2 4 3 4 4 KarlukRiver -3 3 4 1 2 2

Dog Salmon Creek 2 4 4 2 2 OtherAreas Combined 2 5 5 13 2 2 1 a Red Lake system includes the lake, 2 tributariesinto the lake, and 1 outlet tributary. b KarlukLake system includes Karluk,Thumb, and O'Malley Lakes and tributariesflowing into these lakes.

salmon near her Zachar River denning area, but she 2-3 weeks. Frommid-May through June they spentmost typically fished in SturgeonRiver in early summerand of their time in mid-slope habitatfeeding on emergent then ranged in the KarlukLake basin into November. vegetation (Clark 1957, Smith and Van Daele 1988). Mean annualranges of these 4 females rangedfrom 100- Except for animals that denned in the headwaters of 461 km2and averaged211 km2. Uyak, Deadman,and ZacharRivers, substantialmove- Although annualranges (95% minimumconvex) of ment between drainagesto feed on salmon did not begin adultmales (x = 185 km2,SE = 42, n = 6) exceeded that untillate Julyor early August. By late Septemberor early of adultfemales (x = 71 km2,SE = 20, n = 33), only 1 male October,most females had returnedto those locales in traveledoutside the core area. In September1986, that which they would eventually den. Exceptions were animal traveled from the Red Lake area to Brown's females that remained at KarlukLake in October and Lagoon (24.5 km), where a congregationof bears was Novemberto feed on sockeye salmon. feeding on chum salmon, and then returnedto the Stur- Data on adult males suggest they also traveled over geon River drainagein early October. wider rangesin summerthan in otherseasons (Table4). Interdrainagemovement by bearsduring summer was Composite summerranges of males and females were predominantlyassociated with foragingon salmonand it comparable,but males had a largermean areaof primary contributedto relatively large ranges duringthat season use. This may reflect a tendency of males to travel (Table 4, Fig. 2). Because numberof non-denlocations extensivelythroughout their range whereas females were of bears was often limited in spring and/orfall of some inclined to remain in particulardrainages for longer years,seasonal ranges were compared by pooling datafor periods of time. individual bears by season over all years they were Among females (n = 33), annualsummer ranges and tracked. This approachresulted in composite seasonal areas of primaryuse during summer averaged 34 km2 ranges that were largerthan annualseasonal ranges,but (SE = 6) and 12 km2 (SE = 4), respectively. For the 2 should not bias the relative difference in movement years adultmales (n = 6) were monitored,mean areasof patterns between seasons. Mean composite summer annual summer range and primary use were 85 km2 range of females, as well as mean area of primaryuse (SE = 45) and 21 km2 (SE = 6), respectively. The duringsummer, was at least 3 times larger(H = 44.5 and disparityin size of mean annualranges and primaryuse = H 37.1, respectively,P < 0.05) thaneither spring or fall areas during summer appearedto reflect a pattern of range(Table 4). Most females emergedfrom dens during movementbetween areas of concentratedfood supply. late Aprilto earlyMay (Van Daele et al. 1990) andtended Mean annualsummer range of females variedamong to remainin the same drainageof the den sites for at least years (H = 21.4, P < 0.05), rangingfrom 15 km2in 1983 310 BEARS THEIR BIOLOGY AND MANAGEMENT

Table 4. Mean seasonal ranges (95% minimum convex) and areas of primary use (95% harmonic mean) of adult female and male brown bears on southwest Kodiak Island, 1983-1987.

Seasonal range (km2) Primaryuse (km2) Spring Summer Fall Spring Summer Fall x SE x SE x SE x SE x SE x SE

Females (n =33) 13 2 108 22 26 10 14 2 63 8 23 3 Males (n = 3) 27 21 103 60 30 27 99 76 to 61 km2in 1986. Because unequalsample sizes among salmon and then returnedwithin 3 weeks. In September, years may have contributedto this variation,I compared anotherfemale, also with 1 cub, traveled27 km outside the annualsummer ranges of 8 females thatwere continu- her normal range for an undeterminedreason. Three ously trackedfrom 1984 through 1987 (Table 5). Al- other females with unusually large annual ranges though mean summerrange was larger in 1986 than in (x = 246 km2)traveled long distancesbetween spring and other years, variation among years was not significant summer range, as well as during the summer period; (H = 2.1, P > 0.05). This suggests variationamong indi- minimum straightlinedistances they traveled with new vidual bears had a greaterinfluence on size of summer cub litters were 23, 31, and 46 km. ranges than annualfluctuations in food availability. Maternalstatus apparently had little effect on summer Restrictedmovements might be expected in yearsthat movementsor rangeof females. To examinethe effect of females travel with new cubs (Pearson 1975, Miller litterson size of summerrange, I comparedranges of 17 1987) and certainly they limit movement during the females with datain each of 3 maternalcategories. Mean immediate post denning period (Smith and Van Daele summer ranges for females without cubs (x = 26 km2, 1988, Van Daele et al. 1990). However, in this study 2 SE = 7, n = 25), with new cubs (x = 36 km2, SE = 11, females made their longest excursions when traveling n = 19) and with older (>1 yr) cubs (x = 38 km2,SE = 8, with new cubs. In 1 case a female with 1 cub moved n = 30) were similar(H = 1.2, P > 0.05), as were areasof 21 km outside her normalsummer range to feed on pink primaryuse (x = 11-12 km2,SE= 2, H = 0.1, P > 0.05).

DISCUSSION Several studies have documented habitat use and movement patternsof coastal brown bears (Berns et al. 1980, Glenn and Miller 1980, Schoen et al. 1986, Ham- ilton and Bunnell 1987, Smith and Van Daele 1988 and others); collectively they revealed how utilization of salmonvaried between bear populations. Brown bears in British Columbia ranged widely in search of several berryspecies and then restrictedmovements while feed- ing on salmon (Hamilton and Bunnell 1987). On the Alaska Peninsula(Glenn and Miller 1980), bearsmoved proportionatelygreater distances in spring than in sum- mer and fall. Bears traveledto the coastal plain in spring to feed on marinemammal carcasses and ungulateprey; movements were relatively small in summerwhen bears were concentratedalong salmon streams. Schoen et al. (1986) discoveredthat a portionof the AdmiraltyIsland populationdid not feed on salmon in coastal streamsbut insteadforaged in interioralpine and subalpinehabitats. Fig. 2. Composite seasonal ranges (95% minimum convex polygons) of 4 adult On Island,females thatfed on salmon females radio-tracked 4 to 5 consecutive years during 1983-1987, southwest Admiralty usually Kodiak Island, Alaska. remainedon individualstreams and consequentlyhad a SALMONINFLUENCE ON BROWNBEAR * Barnes 311

Table 5. Annualsummer ranges (95%minimum convex) and areas of primary Brown bears in both the TerrorLake and southwest use during summer (95%harmonic mean) for 8 adult females tracked 4 entire years, 1984-1987,on southwest KodiakIsland, Alaska. Kodiak study areas have adaptedforaging patternsthat allow them to exploit available resources successfully. Variation in the and Summerrange (km2) Primaryuse (km2) type, abundance, distributionof x SE x SE foods resultedin dissimilarmovement patterns and sea- sonal distributionsin the respectiveareas. Use of vege- 1984 37 19 12 2 tativecommunities in the TerrorLake area often involved 1985 38 11 16 4 movementalong an elevationalgradient with little travel between movement between 1986 52 22 14 4 drainages. Additionally, streamsto feed on salmon occurredless frequentlyand 1987 34 23 9 2 over a shortertime spanthan in southwestKodiak (Smith and Van Daele 1988). As a result,annual ranges (100% small average home range (19 km2);males frequently minimum convex) of adult females (x = 28 km2) and moved between several streamsand had a largermean males (x = 133 km2)in the TerrorLake study (Smithand home range (115 km2). Van Daele 1990) were much smaller than comparable Brown bears on southwest Kodiak Island traveled ranges on southwest Kodiak (female x = 92 km2;male more extensively in summerthan in springand fall, and x = 219 km2). However, the 2 areas supportedcompa- theirsummer movements were directedprimarily toward rabledensities (1 independentbear/4.5 km2, Terror Lake concentrationsof salmonavailable at varioussites and/or vs. 4.7 km2,southwest Kodiak; Barnes et al. 1988). Thus, separate time periods. Compared to the study areas variation in size of annual ranges between the areas referredto above, southwestKodiak apparently offered a probablyreflected differences in availabilityand exploi- more diverse salmon resource in terms of distribution, tation of habitat resources rather than overall habitat abundance, and species diversity. Conversely, other quality. resourcessuch as alpineforage (Atwell et al. 1980, Smith It is unclearwhy home rangesreported by Bers et al. and Van Daele 1988), berries, and ungulate prey were (1980) for the KarlukLake drainage (female x = 11- less diverse on southwestKodiak. The salmon-oriented 14 km2,male x = 24 km2)were less thanthose recordedin movement patternsobserved in this study, however, do this study. Because most data in the earlierstudy were not diminishthe importanceof otherforage. Vegetative collected duringthe fall season, it is possible that some items are an essential componentof the bear diet in the movement to and from KarlukLake was not detected. study area (Clark 1957). Also, some bears may range entirely within the Karluk Movementand habitat use patternsevaluated concur- Lake drainage because the area provides an unusual rently in this study and in the TerrorLake region of diversity of forage, cover and denninghabitat (Bers et northernKodiak Island (Smith and Van Daele 1988) al. 1980). revealed contrastingforage strategies for 2 essentially Femalesin southwestKodiak usually occupied annual contiguousareas. Althoughbears in the TerrorLake area ranges <80 km2;during summer they tended to congre- were attractedto salmon during summer,phenology of gate in areas where salmon were abundant. For several various vegetative communitieswas most predictiveof animals,consecutive locations in particularstream drain- movementpatterns. Emergingherbaceous species were ages indicatedlimited movement while they were fishing importantspring foods in both areas. During July and that stream. Although some females were observed to early August, though, bears typically grazed on alpine move back and forth between distant fishing sites in vegetation in the TerrorLake area while bears in south- periodsof < 10 days, the datasuggest this patternwas less west Kodiak were congregatingalong salmon streams. common. Alpine habitatcomparable to thatfound near Terror Lake Maternal status apparently did not affect general is uncommon in southwest Kodiak and salmon do not movement patterns of females during summer; mean become abundantin the TerrorLake area until August. summer ranges were similar during years they were Salmon abundancedeclined after mid-Septemberin the alone, with new cubs, and with 1- or 2-year-old cubs. TerrorLake areaand bearsspent increasingtime in mid- Five of 17 females had largestsummer ranges when they slope habitatsfeeding on berries.A less pronouncedshift were accompaniedby new cubs. However,females with to mid-slopehabitat was evidentin southwestKodiak and new cubs probablyaltered diel movements or selected salmoncontinued to hold or attractbears to lowlandareas specific fishing sites to avoid interactions with other into late fall (Bers et al. 1980, this study). bears (Stonorov and Stokes 1972, Mattsonet al. 1987). 312 BEARS-THEIR BIOLOGY AND MANAGEMENT

Whenobserved for extendedperiods from ground camps, MANAGEMENTIMPLICATIONS they tendedto separatethemselves from otherbears and The strong link between salmon and brown bears in fish at times when the fewest bearswere along streamsor southwest Kodiak Island deserves the attention of re- shores. source managers. Key elements that should be consid- Dataon adultmales revealed patterns somewhat similar ered are salmon escapementinto streamsand protection to those of females but with more extensive travel. They of anadromousstream habitat from excessive human fished at the same sites used by females and in the same disturbance.Recently the AlaskaDepartment of Fish and time periods. They were often observed fishing or Gameand the KodiakNational Wildlife Refuge coopera- bedded within 30 m of other single bears or family tively establishedan escapementlevel of sockeye salmon groups. Mean annual summer range of adult males into the FrazerLake system thatincorporated a mortality exceeded that of females; the data indicatedthat males estimate due to bear predation(T. Chatto, Kodiak Na- traveledbetween streamsmore frequentlyand were less tionalWildlife Refuge, pers.commun.). This conceptof inclined to remainalong particularstreams for extended allocatingfish to brownbears should be extendedto other periods. salmon species and in other watersheds importantto Four adultfemales rangedover unusuallywide areas bears. and generallyfollowed a patterndescribed by Bers and Improveddata on timing and numbersof some anad- Hensel (1972) as use of separateactivity areas. Female romousfish runs would enhancethe ability of managers No. 722, for example, denned in the same rock cavity to detect significant declines in salmon escapements above Uyak Riverfor 5 consecutiveyears; in late Juneor before they cause importanteconomic and biological earlyJuly of each year,regardless of maternalstatus, she impacts. Forexample, the increasingcommercial fishery traveledto Dog SalmonCreek and/or Karluk Lake to feed for coho salmon,if continued,could seriouslyreduce an on sockeye salmon and then in mid- to late August importantlate seasonfood supplyfor bearsin manylocal returnedto the Uyak River to feed on pink and chum areas. Unfortunately,escapement data for coho salmon salmon. Similar although less consistent movement are incompleteor absentfor many streams. patternswere followed by 2 animals that denned in the Managersshould also recognizethat projects to intro- DeadmanRiver drainage and 1 thatdenned in the Zachar duce or increasethe abundanceof salmon can markedly River watershed;each of these animals traveled to the affect bears. It is unknownwhether or not establishment core study areaduring summer and fished for salmon at of a sockeye runin the FrazerLake system increasedbear varioussites. Because chum, pink, and coho salmon, as density in that watershed,but it clearly influenced the well as alpineforage, were readilyavailable in the Uyak, seasonaldistribution of bears. Feeding congregationsof Deadman, and Zachar drainages, movement of bears bears on lower Dog Salmon and Pinnell Creeks are a from those drainagesinto the core study areaapparently directresult of that salmonenhancement project. Future was not motivatedby food availability. It is more likely plansto establishor rehabilitatedepleted salmon popula- the animals were following traditionalmovement pat- tions in brown bear habitat should recognize that bear terns established by several generations of maternal movement patternscould be altered and new areas of females. concentrationmight develop. The extent that bears and Consistentyear-to-year use of specific fishing sites by bear/humaninteractions are affected will depend on individualbears, regardless of annualrange size, implied specific characteristicsof each project. thatlearned behavior played an importantrole in locating Reliable evaluationof bear habitatneeds on Kodiak salmon. However, deviation from what appearedto be Islandwill requirecurrent information on bearutilization established patternsoccurred often enough to suggest of salmon streamhabitat. Thus, I recommendthat aerial that bears may also explore their ranges in search of surveys of bear concentrationson selected streams be salmon or other foods. Such activity would provide continuedas a means of documentingtrends in bearuse, and detect- animals an opportunityto exploit seasonal or annual relatingbear use to salmonescapement data, fluctuationsin food abundance.Regardless of whatclues ing potentialsources of disturbanceto bears. bearsused to locate salmon and otherfoods, behaviorof Protectionof bear feeding sites on the Kodiak Na- individualanimals was an obvious influence on move- tional Wildlife Refuge may require regulationsto ex- of ment andrange; differences among individuals using the clude or limit recreationaluse. The currenttrend et al. same habitats appearedto mask the effects of annual expandinghuman activity on KodiakIsland (Smith variation in food abundance and distributionon bear 1989) can be expected to focus recreationaluse in areas movement. such as KarlukLake, Red Lake and the lower Ayakulik SALMONINFLUENCE ON BROWNBEAR * Barnes 313

River that offer good floatplane access. The stress of KISTCHINSKI,A. A. 1972. Life history of the brown bear (Ursus arctos L.) in north-eastSiberia. Int. Conf. Bear Res. and avoiding humans will probably have an adverse affect on 2:67-73. some bears et al. some Manage. (Mattson 1987). Alternatively, MATTSON,D.J., R.R. KNIGHT,AND B.M. BLANCHARD.1987. animals can be expected to habituate to humans and The effects of developmentsand primary roads on grizzly reduce probability for their survival (Herrero 1985, bearhabitat use in Yellowstone NationalPark, Wyoming. Archibald et al. 1987). Restrictions on recreational use, Int. Conf. Bear Res. and Manage. 7:259-273. AND J.F. THILENIUS.1983. if necessary, should be directed at specific tributaries or MEEHAN,W.R., Safety in bear country:protective measures and bullet performanceat of shoreline, and limited to those time segments periods shortrange. U.S. Dep. Agric., For. Serv., Gen. Tech. 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